Field of the Invention
The invention relates to a data carrier of plastic in card form, which can receive one or more chips in a recess which is closed with a cap. The chip or chips may be mounted on so-called MID conductor tracks by bare-chip mounting, potted with a plastic composition for instance, and then covered with a cap that covers at least the recess. In most cases the cap covers the entire flat side in which the recess is formed.
The term "MID technique" is understood to mean the formation of three-dimensionally extending conductor tracks, which are applied to a three-dimensional structured substrate (MID is an acronym for molded interconnect device, a three-dimensionally injection-molded circuit carrier)
Data carrier cards are often called chip cards, since as a rule a chip is included as a data memory or data processor.
Either a module comprising a small printed circuit board with chip mounted on it is inserted into a cutout of a base body of a data carrier card, or a chip mounted on a leadframe is spray-coated with plastic, or an MID substrate in card form is used, in which the chip is mounted, potted, and finally covered with a cap. Each of these cards may be provided over large surface areas with labels of any type. For data transmission to the outside or to the card, contacts need merely be kept free. On the other hand, contactless transmission is also possible in principle, via transmitting and receiving units.
Such cards can be provided with injection molded labels. For instance, various chip cards can be provided with labels in a single operation. For instance, plastic labels are held electrostatically in an injection mold, and after a module with electrical terminals that comprises a chip and circuit board is introduced, the plastic form can be injected, so that the chip module, terminals and labels are bonded to a card.
Such cards according to the prior art involve complicated and expensive assembly, however. With a chip pre-mounted on a substrate, insertion into the cards is a complicated process. Spray-coating a leadframe with plastic is also very expensive in terms of systems technology, because the pre-mounted leadframe has to be manipulated in the injection molding machine. This is particularly true since the chip must be protected beforehand against damage, in a separate work step, for instance by being sheathed with a plastic composition. Thus injection molding processes are disadvantageous not only because of the relatively high temperature stress for semiconductor components, but also because very expensive systems are needed. The injection molding process, which is associated with straightening two labels and the module inside the injection mold, is very vulnerable to error. It is essential that this step be taken at the end of the value addition chain, with the chip already installed. If there is a flaw in the relatively inexpensive plastic part, the expensive chip together with the entire card thus becomes a reject.
A further development in the prior is a data carrier card with an MID card body. The chip is inserted into the base body of the card here nearly at the end of the value addition chain.
Next, on the side where the chip has been inserted into a recess, a cap is applied. The flat sides of the card can be finished by imprinting or by attaching labels. The chip is thus no longer exposed to the thermal stress of an injection molding process.
Since the known data carrier cards or chip cards are produced in very large numbers, the prior art production methods include further disadvantages. For instance, at least the base body of the card, chip, cap and label as well as adhesive must be delivered to the production process.